(Reuters) - Fixing Flint, Michigan's lead-contaminated drinking water infrastructure could cost as much as $1.5 billion, the city's mayor said on Thursday after meeting with the governor to discuss the crisis, according to Detroit newspapers.

Flint Mayor Karen Weaver said in Lansing, the state capital, where she met with Governor Rick Snyder, that the cost to fix or replace the city's water pipes has been estimated in a range of millions of dollars to up to $1.5 billion, the Detroit News and Detroit Free Press reported. A spokeswoman for the mayor could not be reached to comment.

However, Keith Creagh, interim director of the state's Department of Environmental Quality, said it was premature to estimate the total costs, according to the governor's spokesman.

The financially strapped city was under the control of a state-appointed emergency manager when it switched its source of tap water to the nearby Flint River in April 2014 from Detroit's water system to save money.

Flint, about 60 miles (100 km) northwest of Detroit, returned to Detroit water in October after tests found some children had elevated levels of lead in their blood and lead was found in higher-than-acceptable levels in the water.

Snyder on Thursday apologized for a second time for the state's role in the crisis.

"This is a situation that no one wished would have ever happened, but it has happened," Snyder told reporters. "We're taking this extremely seriously."

Snyder promised more testing and more filters in Flint, as well as a "suite of services to improve things in Flint for this unfortunate situation that I do apologize for."

This week, the U.S. Attorney's Office in Detroit said it was investigating the lead contamination of Flint's water and Snyder declared a state of emergency in Gennessee County, which includes Flint, authorizing additional state resources to address health and safety issues.

Snyder apologized in late December for the state's mishandling of the situation and accepted the resignation of the state official whose agency, the Department of Environmental Quality, is responsible for overseeing water quality. Flint residents have filed a federal lawsuit accusing the city and state of endangering their health.

The Detroit News, citing internal emails, reported on Thursday that Snyder's chief of staff, Dennis Muchmore, recognized as early as July that Flint's residents were "basically getting blown off by us" in the state's response to the lead contamination problems.

Dave Murray, the governor's press secretary, said Muchmore had been meeting with Flint community leaders throughout the year and was following through on community concerns.